Inflammatory bowel disease (IBD) refers to a collection of intestinal disorders causing inflammatory conditions in the gastrointestinal tract. The primary types of IBD are ulcerative colitis (UC) and Crohn's Disease (CD). These diseases are prevalent, with about 1.86 million people diagnosed globally with UC, and about 1.3 million people diagnosed globally with CD.
Each of these forms has various subclinical phenotypes characteristic of severe forms of IBD that are present in sub-populations of CD and UC patients. One such condition is obstructive Crohn's disease, which can result from long term inflammation that may lead to the formation of scar tissue in the intestinal wall (fibrostenosis) or swelling. Both outcomes can cause narrowing, or obstruction, and are known as either fibrotic or inflammatory strictures. Severe strictures can lead to blockage of the intestine, leading to abdominal pain, bloating, nausea and the inability to pass stool. As another example, penetrating disease phenotypes characterized by bowel obstruction or internal penetrating fistulas, or both, often resulting in complications associated with IBD, including for e.g., intra-abdominal sepsis.
Unfortunately, there are a limited number of therapies available for IBD patients, and the development of new therapeutics has been hampered by sub-optimal results in clinical trials. Existing anti-inflammatory therapy such as steroids and tumor necrosis factor (TNF) inhibitors are typically use as a first line treatment for treating IBD. Unfortunately, a significant number of patients experience a lack of response or a loss of response to existing anti-inflammatory therapies, especially TNF-alpha inhibitors. While the patient is treated with an anti-inflammatory therapy that is ineffective, the disease worsens. Surgery, in the form of structureplasty (reshaping of the intestine) or resection (removal of the intestine), is the only treatment option for patients that do not respond to first line therapies. Surgical treatments for IBD are invasive, causing post-operative risks for an estimated third of patients undergoing surgery, such as anastomotic leak, infection, and bleeding.
The pathogenesis of IBD is thought to involve an uncontrolled immune response that may be triggered by certain environmental factors in a genetically susceptible host. The heterogeneity of disease pathogenesis and clinical course, combined with the variable response to treatment and its associated side effects, suggests a targeted therapeutic approach to treating these diseases is best treatment strategy. Yet there are very few targeted therapies available to IBD patients, especially those patients who may be non-responsive to existing IBD therapies (e.g., anti-TNFa inhibitors). Accordingly, there is a need for novel therapeutics to treat IBD that specifically target enzymes involved in IBD pathogenesis.